Serial protocol SendData only prefix with size in case of variable size content (i.e. SetTraceVariableList)
<xsd:attribute name="BuildPath" type="xsd:string" use="optional" default=""/>
<xsd:attribute name="Command" type="xsd:string" use="optional" default="make -C"/>
<xsd:attribute name="Arguments" type="xsd:string" use="optional" default="BEREMIZSRC=%(src)s BEREMIZCFLAGS=%(cflags)s MD5=%(md5)s USE_BEREMIZ=1 FROM_BEREMIZ=1 --quiet"/>
<xsd:attribute name="Rule" type="xsd:string" use="optional" default="all"/>